Probably not significantly different from the dongle being plugged into one of those dual-port sockets. That being said, having a BT dongle right next to an act

Probably not significantly different from the dongle being plugged into one of those dual-port sockets. That being said, having a BT dongle right next to an active USB 3 cable is known to cause interference, see [0]. [0]: https://www.usb.org/sites/default/files/327216.pdf https://www.usb.org/sites/default/files/327216.pdf